below is a list of security mechanisms and threats. For each security mechanism, indicate whether it is very effective, mostly effective, partially effective, partially ineffective, or not effective against the listed threats.

Provide a brief explanation for each answer.

For some combinations there may be more than one possible effectiveness depending on the scenario, so use partially effective, mostly effective, or mostly ineffective to indicate these borderline cases (and the situations where this can vary). eg. House Keys are a mostly effective security (since they are very effective unless they are lost/stolen/copied)

List of security and threats (below):

Security mechanisms: Packet filter, X.509 certificates, sandboxing, encryption

Threats: malicious insider & worm